Backing plate for sanders



Fume 3 B924.

F. L. LANE EQGAN BACKING PLATE FOR SANDERS Filed July 11, 1923 Patented .lune 3, 1924.

oFFlcE,

FRANKLIN L. LANE, OF BLOIT, WISCONSIN, ASSIGNOR TO l?. B. YAT'ES MACHINE COMPANY, 0F BELOIT, WISCONSIN, A. CORI?ORAIIONY OF WISCONSIN.

BACKING PLATE FOR SANDERS.

Application filed July 11,

To all whom t may concern.'

Be it known that I, FRANKLIN L. LANE, a citizen of the United States, residing at Beloit, in the county of Rock and State of Wisconsin, have invented certain new and useful Improvements in Backing Plates for Sanders, of which the following is a specification.

Heretofore in sanders for smoothing the surfaces of wood, particularly in edge sanders, it has been customary to employ an endless sand-,belt with suitable abradant material on one face', co-operating means, such as drums or pulleys, around which the belt passes constituting driving means for it, and an associated metal backing-plate along one stretch of the belt to hold it up to the work, such plate having a padding or cushion on its front face on which the belt bears and slides, such cushion being coated or treated with a suitable lubricant to reduce friction, such as a composition or mixture of paraffin and graphite.

Such a construction, while satisfactory for many kinds and types of work, will not perform the sanding or smoothing or polishing operation with sufficient accuracy when exactness and precision are prime requisites, because of the yield or give of the cushion, which permits a corresponding deflection or deformation of the belt.

I have found that to secure precise and exact results, the back face of the sand-belt must bear and travel directly on the face of the rigid and unyielding backing member without any intervening or interposed yielding or cushion element.

This means, of course, that the use of an antifriction medium is practically precluded, because there is nothing back of the belt to hold or accommodate it, and hence excessive heat is generated in the metal plate causing warping and twisting of the latter out of true, thus resulting in inaccurate and imperfect work.

This fault or defect I have found can be satisifactorilj)T remedied or overcome by providing the plate with adequate cooling facilities to carry away a suiiicient amount of the friction-generated heat, thus assuring that the plate, although the belt slides in direct contact with it, will maintain its true orm and'preserve its operative plane surace.

To enable those skilled in this art to have 1923. Sei-iai No. 650,746.

a full and complete understanding of `this invention and its various structural and functional advantages, in the accompanying drawing forming a part of this specification and throughout the views of which like ref erence characters designate the same part, I have illustrated a desirable and preferred embodiment of the invention.

In this drawing: Figure 1 is a plan view of an edge sander equipped with the new backing-plate, the

cover of which is omitted from-the illustration and Figure 2 is a fragmentary elevation of the structure shown in Figure 1 with certain parts broken away to more clearly depict the internal construction.

By reference to this drawing, it will be seen that the appliance includes the usual work-table 11, a rotary drive-pulley 12, and an idler tightening-pulley 13 which may be easily adjusted by suitable means to take up slack in the endless sand-belt or band 14 which encircles or extends around both drums or pulleys.

All of this is of the old and well-known construction and need not be described more in detail.

Instead of the usual and customary metal backing-plate faced with a felt or other pad `or cushion suitably supplied with an eiiicient lubricant, and in order to avoid the somewhat inaccurate results incident to the employment of such a structure because of the elasticity or resiliency of the interposed cushion or backing, in the new and improved structure, a rigid, hollow, watercooled plate 15 is used without any intervening cushion and without any lubricant.

This plate is mounted on appropriate brackets or` standards 16 and 17, and comprises a front-wall 18 with a plane outer face, a parallel inner wall 19 spaced away from the front wall, end-walls 21 and-22 with the front section 18 extended or projected beyond the same, a bottom wall 23, and a plurality of upright connecting webs 24 joining together the front and rear walls at intervals, the webs not extending down to the bottom wall hence permitting a free circulation of water, which Lis admitted through a pipe 25 near the bottom of the chamber and which when heated discharges through an outlet pipe 26 near the top of the other end portion of the compartment.

removabley cover-plate 27 normally closestlie top of the otherwise open Waterchamber.

lt will be perceived that the endlss sandbelt or band bears or presses directly on the front-face of the backing-member, and,y inasmuch as such surface of the backing element is a true plane, and is maintained against distortion due to heat by reaso-n of the rapid absorption and removal of its heat' units by the flowing Water, accurate andvprecise smoothing or polishinguwork may bey performedby the beltby reason of its direct co-action with such non-deformable backing-member,

lNere it not for an efficient and effective cooling means associated with the plate, and particularly because of the absence of a lubricantj the plate would have a distinct tendency to deviate from its proper form resulting in inaccurate Work unsuited to meet some high standards at present employed.

Those skilled in this art Will readily understand -that they invention is not limited and restricted to the precise and exact details of structure presented and that these may be modified within comparatively Wide limits without departure fromuthe heart and essence of the invention and Without the sacrifice of any of its substantial benefits and advantages.

I claim:

ln a. sander, thefcombination of an end.-

less sand-belt, means to drive said belt,` a

hollow backing-plate against an cuter face of which tliebelt directly bears, means to admit a cooling fluid to the interior of said backing-plate, and means to allow the discharge of said fluid from said backing-plate at a point other than that surface thereof covered by said sand-belt.

ln witness whereof l have hereunto `set ymy hand andseal.

rRANKLiN L. LANE [11.45.] 

